Sorry about that, the serial monitor and a LCD. So the only way to do that is with a if statement, there isn't a built in way to do it? I am working with two number and at times one might be greater than 100 and the other might be less than 100.

It's all rather academic from the perspective of being able to use sprintf(), but it never hurts to have an understanding of what's going on beneath the covers, and I think it's always useful to know that the variety of C library functions in those modules are available for your usage within Arduino sketches by default.

Could be useful to have a list of functions avalible that don't require an include directive?

That might be a moving target - I don't suppose the Arduino development team consider that the set of implicitly-included headers for any given library or for the environment as a whole is parts of the defined interface for that library or environment. (Microsoft don't either; they're always changing things around and breaking code that took the implicit includes for granted.)

I only provide help via the forum - please do not contact me for private consultancy.